Triple valve for air-brakes.



9. 9 8., U.. u A d e t n e t a .T om 7 3, 0 3 6 0. N

(Application led Oct. 14, 1898.)

(No Model.)

Il F "Il:

if @mv mams PETERS on, wenn UNITED STATES;

PATENT OFFICE.

WILLIAM n. MANN, or BALTIMORE, MARYLAND TRIPLE VALVE FoR AIR#BRAKES sPncIFicAToN forming part of Letters ratent No. esovs, dated Agus s, 189e.

p Application nea october 14,1898. stanno. staten.` oromodein To all whom, it may' concern I A l Be it known that I, WILLIAM B. MANN, of Baltimore, Maryland, have invented anew and useful Improvement in Triple Valves for Air-Brakes, which improvement is fully set forth in the following specification.

My invention relates to vtriple-valve mech- -anism employed in connection with air-brake systems on railroads, and more especially to that class of triple valves known as quickaction valves.

In order to secure the desired quick action of the triple valves, it has been found neces- Y sary to serially vent the train-pipe, preferably at or near each triple valve, by opening a passage leading-from thentrain-pipe either to the atmosphere or` to the brake -Acylindeiu Heretofore in that class of quick-action triple valves which vents the train-pipe into the brake-cylinder through the triple-val vc piston l the train-pipe air has been conducted into the triple-valve chamber, where it min gledwith air from the auxiliary reservoir, the two airs thus combined passing together from the valve-chamber into the brake-cylinder. Now in order to secure the maximum pressure in the brake-cylinder in the shortest space of time the train-pipe air should be conducted to the brake-cylinder in advance of the'auxiliary-reservoir air. This not only secures greater pressure in the brake-cylinder, but it also produces the quicker serial venting of the train-pipe, and hence the-more nearly simultaneous application of all the brakes 'on a long train of'cars.

The presentin'vention has for its object,

therefore, to produce a'triple valve in which upon a full traversefof thev triple-valve .pis-

ton trainpipe airshall pass directly through I said piston to the brake-cylinder without entering the triple-valve chamberf'and in. ad-A .Vance of auxiliary-reservoir air.

To this end the invention' consists of a triple valve of any desired construction and its actuating-piston which, with the valve, moves in a suitable valve-casing, said piston having a hollow stem or rod leading through the. triple-valve rcasing and V.communicating at one end directly with' the brake-cylinder in advance of the port controlled by the triple valve and at the other end with the train- Furthermore, the invention consists of a` hollow triple-valve piston stern or rod com'- municating at one end With the brake-cylin der and Vat the other end with the train-pipe and a valve controlling said communication, which valve is subjected to differential pressures, alternating first on the train-pipe side and then on the brake-cylinder side of the Valve when the triple valve piston is suddenly given its full traverse in emergency application of the brakes.

. The invention'also resides in certain details of construction, which will be fully pointed out in the claims. Y

. The same inventive idea may find mechanical expression in various forms, and for purposesof illustrationl have shown one of these forms in the' drawings forming a part of this specilication, in Which- Figure 1 is a longitudinal vertical section of a triple valve and its cooperating elements, showing the parts in the position which they occupy when the brakes are released. Fig. 2 is a similar view showing the parts in the position they occupy when making an emergency application of the brakes; and Fig. 3 is a like view, the parts being shown in the position forservice or graduating application of thebrakes.

-In-the several-iigures of the drawings, in which like letters indicate like parts, A is the'tripl'elvalve casing; B, the triple valve, which may be of any desired construction; C, 'the valve-operatingpiston; D, the passage leading from the train-pipe; E, the passage .leading toV the` auxiliary reservoir, and Fy thepassage to the brake-cylinder. ,Gfisthe vent-port leading to the atmosphere and, as shown in Fig. l, is normally in communicationwith the brake-cylinder; but when 'the 4brakesare to be applied either in emergency or service stops such` communication'is closed, as-shown in Figs; 2 and 3.

The piston C has an opening 4through its center and a hollow stem C extending therefrom through the triple-valve chamber B' and fitting vair-tight inta cylinder H, formed in theend of the valve-casing adjacent to the passage F. On y the front or train-pipe side IOO extension and through the piston C when the valve K is unseated. Attached to the opposite side of the valve K from the cylinder la is a iston k" workin@ in a c linder k3 formed p 9 D 7 in an enlargement of the hollow piston-stem C. The cylinder 7c3 at the rear of piston 7s is in direct communication atV all times with the train-pipe through the passage h4, while the cylinder to the front of piston 7c" is at all times in communication with the brakecylinder through the space 705 between the hollow piston-stem C and the cylinder 768 and through the hollow stem C', past the checkvalve b', cylinder l-I, and passage h leading from said-cylinder H to the passage F.

For convenience inv construction thehead -A of the valve-casing A is formed with a chamber' a therein, which chamber is closed on its outer side by a screw-plug a2, which hasl an' inward extension a3 loosely entering the cylinder k on the valve K and forming in connection with said 'cylinder akind of dashpot; cross-sectional areal ofthe tubular extension O2 is less than the cross-sectional area of the cylinder k3 and that when-the valve K isl seated, as shown in Fig. 1, the area of the valve exposed to train-pipe pressure is less than the area of the piston 7a" exposed to a like pressure in the cylinder k3, and consequently the valve K is held on its seat.

The operation is as follows: Suppose the parts to be in position shown in Fig. l, with the brakes released. Then air at train-pipe the spaces and passages of the triple valve and be exhausted to the atmosphere through port G and the exhaust-duct g of the triple valve.

the auxiliary reservoir and triple-val ve chamber will cause the piston C to quickly make its 'full traverse to the position shown in` Fig. l claim as new, and kdesire to secure by Letters 2,-thus operating the triple valve in the wellknown way to close the exhaust and open? communication from the auxiliary reservoir to the brake-cylinder.

It will be observed that the internalv unseated and the train-pipe air passes around the cylinder 7c3 through the hollo'w rpistonstem C', cylinder H, check-valve b', and passage h to the passage F, leading to the brake-cylinder. It will bel noted that the track of the air from the train-pipe to the brake-cylinder is comparatively unobstructed, while the air from the auxiliary reservoir to the brake-cylinder has to pass'through the restricted port h. The result ofthisis that the volume of the air from the trainpipe reaches the brake-cylinder in advance of the air from the auxiliary reservoir, thereby increasing the volume of air taken from thetrai'n-pipe to the brake-cylinder, which results in an increase in the ultimate pres.- sure in the brake-cylinder, as well as a quickening of the serial venting of the trainpipe throughout the train, because the air in passing from the train-pipe into the `brake-cylinder encounters little or no pressure from the auxiliary reservoir. Owing to the loose fit of the piston-plug as in the cyl-- inder It, the air therein, which has been momentarily compressed to a point above trainpipe pressure, escapes, thereby establishing an equilibrium of pressure withinv the cylinder 7o and the train-pipe. When this equilibrium has been established, the differential pressures on the valve K and the piston 7c will cause the seating of the valve. This differential pressure is due to the fact that the passage 7a4 between the cylinder 7c3 and the train-pipe is so restricted that the pressure in the train-pipe is more rapidly reduced than is the pressure in said cylinder 7c3, which latter pressure has been primarily increased by the opening action of valve K when assuming position shown in Fig. 2.

It will of course be understood that the passage 7r4 is not a restricted channel, but is a space extending around the cylinder lo and has a cross-sectional area substantiallyequal i to that in the tubular extension C2 around pressure of, say, seventy pounds will enter all g the'plug a3 when the valve K is open, as

shown in Fig. 2, so that the train-pipe air has casing, except hollow piston-stem C', cylinder ll, land passages h and F, all of which will v an unobstructed passage on its way to the brake-cylinder. Should the train break in two or the train-pipe be otherwise broken,

2 the check-valve h' would. prevent the escape If now the pressure in the train-pipe be sudi denly lowered, say, ten pounds for the purpose of securing an emergency application of E the brakes, the seventy pounds pressure in; ton 7s, the check-valve may, if desired, be

of air from the brake-cylinder and consequent release of the brakes. When a light spring is employed in the cylinder k3 behind the pisdispensed with.

Having thus'described my invention, what Patent, is-

' l. The combination of Aa train-pipe, auxiliary reservoir, brake-cylinder and ytriple valve, through the triple-valve chamber and port b `l By the sudden movevrod connecting the train-pipe with the brakecylinder and a differential piston-valve normally closing said passage, substantially as described.

IOC

2'. The combination of the train-pipe, auxiliary reservoir, brake-cylinder, triple valve, and its operating-piston, with a hollow rod opening at one end to the train-pipe and at the other end to the brake-cylinder, a differential piston-valve controlling the passage of air through said hollow rod and normally having a preponderance of air-pressure on the brake-cylinder side of said valve, and means reversing the preponderance of air-pressure on sai'cl valve when the triple-valve piston is given its emergency traverse, substantially as described. l

3. The combination of the train-pipe, auxiliary reservoir, brake-cylinder, triple valve and its operating-piston with a hollow piston-rod operatively connecting said piston and triple ing witnesses. p

WILLIAM B. MANN; Witnesses: v

HARRY C. MATHIEU, JOHN B. SANNER. 

